Friday, March 12, 2010

Science and Politics

Daniel Sarewitz in Slate: "It turns out that science contributes most to politics when nobody really cares that much about it."

The author, claims that environmental issues seem to get more intractable, not less, when there is more science, since both sides can find some science to back up their positions. He says things were better when clean air and clean water legislation went through fairly quickly. Now, Yucca mountain as a site for nuclear waste disposal is never a slam-dunk for either side. This is OK as far as it goes, but he could go farther. Aristotle said politics is the master science or pursuit, partly because it determines which others are studied, to what extent, etc. We see examples today of people apparently committed to science who would rather be morally and politically "correct" than to stick to what the science says.

Sarewitz doesn't mention that the environmental movement may have invited a backlash with high-profile campaigns like the ones against acid rain or nuclear power--there was little attention to the costs and benefits of what was proposed, which is really all that decision-makers need to know. There was an emotional appeal to the idea that human actions are screwing things up somehow, and government needs to protect both us and nature. Climate change is the mother of all such theories.

My hobby horses: health and diet issues are often driven not by science but by fashionable ideas of what is aesthetically appealing. It used to be a status symbol to be at least somewhat fat--a sign of prosperity. You had to be rich to get fat. Now in the developed world practically everyone can get fat, so the rich make it a point to stay thin. Amazingly, there is a lot of argument to the effect that skinny is healthy, a sign that you have self-respect and discipline, that it makes you all-around a good person--with little bits of science or pseudo-science thrown in. There is a widespread sense that supermarket food--our most heavily regulated industry--is probably bad for you, and something else, harder to acquire or prepare, less appetizing, more expensive, possibly available only to the rich, is better for you.

Sarewitz sensibly says the case about costs and benefits needs to be made when it comes to specific proposals to deal with climate change. He also says: "Yes, there is a robust scientific consensus that human activity is causing the atmosphere to warm up."

I don't know if this is true, and I'll probably never read the scientific journals to find out. I think adding "robust" to "consensus" is an attempt to win a debate, and "scientific consensus" isn't quite the same as "truth." To some extent a fairly small group of people has been able to establish a brand new climate science, and then decide who counts as a climate scientist, who is published, etc. My understanding is that no one has established a dramatic warming in the 20th century. Proxy data from before about 1850 is even more uncertain.

Whether any warming trend appears in the data depends to some extent on the methods that are chosen to select the most reliable monitoring stations, average them, and process or homogenize the data. Different methods yield different results, and part of the debate over CRU and IPCC have to do with whether the famous "warming" results can pass tests of statistical significance. It makes at least some difference whether there was a warming period, comparable to the 20th century, in both the medieval era and a few hundred years BCE. Those earlier warmings were presumably not man-made, and they do not seem to have been remembered as a crisis or calamity.

The most dire predictions of warming, etc. follow from the belief that there will be a feedback effect, and the temperature will increase at a much faster rate than the one claimed for the 20th century. That there is a greenhouse effect, I believe there is no doubt--likewise that man-made CO2 has increased dramatically since about 1850. But is the whole system closed in such a way that a small temperature increase can only lead to a large temperature increase? Or are there other factors at work--releasing heat, neutralizing it, or indeed causing cooling? I don't know, but I believe there is genuine debate about all of this.

When all of these questions are raised, the standard move is to refer to "obvious" developments: Arctic ice, Antarctic ice, glaciers, methane under the Arctic ocean, and Al Gore's farm in Tennessee being less lush and green than it was when he was a child. I believe each of those needs to be studied on its own. It's not clear any or all of these developments co-relate with the increase in man-made CO2. Yet for many people, it is a minimal test of sophistication and decency to say that they do. One wants to be on the right side.

Meanwhile, h/t to Bishop Hill for a reference to an abstract in a medical journal: "In the last 20 years there has been a progressive decline in the honesty of scientific communications."

Also a judge has finally ruled that thimerosal, a one-time additive to a common childhood vaccine, does not cause autism.